Combining Texts

All the ideas for 'Letters to Edward Stillingfleet', 'Consciousness, Philosophy and Mathematics' and 'Modal Logic within Counterfactual Logic'

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9 ideas

4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / h. System S5
14626 In S5 matters of possibility and necessity are non-contingent [Williamson]
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / b. Intuitionism
8728 Intuitionist mathematics deduces by introspective construction, and rejects unknown truths [Brouwer]
9. Objects / D. Essence of Objects / 3. Individual Essences
15990 Every individual thing which exists has an essence, which is its internal constitution [Locke]
10. Modality / A. Necessity / 1. Types of Modality
14625 Necessity is counterfactually implied by its negation; possibility does not counterfactually imply its negation [Williamson]
10. Modality / B. Possibility / 8. Conditionals / a. Conditionals
14623 Strict conditionals imply counterfactual conditionals: □(A⊃B)⊃(A□→B) [Williamson]
10. Modality / B. Possibility / 9. Counterfactuals
14624 Counterfactual conditionals transmit possibility: (A□→B)⊃(◊A⊃◊B) [Williamson]
10. Modality / C. Sources of Modality / 1. Sources of Necessity
14531 Rather than define counterfactuals using necessity, maybe necessity is a special case of counterfactuals [Williamson, by Hale/Hoffmann,A]
11. Knowledge Aims / B. Certain Knowledge / 1. Certainty
15994 If it is knowledge, it is certain; if it isn't certain, it isn't knowledge [Locke]
15. Nature of Minds / C. Capacities of Minds / 2. Imagination
14628 Imagination is important, in evaluating possibility and necessity, via counterfactuals [Williamson]